In the semiconductor industry, devices are fabricated by a number of manufacturing processes producing structures of ever-decreasing size. As the critical dimensions for semiconductor devices continue to shrink, there is an unyielding need to improve the cleanliness of the processing environment within a semiconductor process chamber. Such contamination may be caused, in part, by chamber components. For example, contamination may be caused by gas delivery components, such as a showerhead.
Many bulk ceramic components include small apertures that allow for process gas flow. These apertures are usually drilled after performing a sintering process, which often results in rough internal surface finishes. Such rough interior surfaces serve as sources of on-wafer defects, since they are directly in contact with the flow of the process gases. To improve upon on-wafer defect performance, particulates can be at least partially removed, for example, from the rough internal apertures by thermal oxidation processes and by radio frequency (RF) conditioning of the component after thermal oxidation. However, some components, such as showerheads, often involve more than 100 hours of RF conditioning prior to using in a semiconductor process chamber in order to satisfactorily reduce particles.